In Okinawa Prefecture, Japan, red soil erosion from the upland fields is one of the main causes of marine pollution. Vetiver (Vetiveria zizanioides) has been planted as a green belt in wide areas in the Okinawa Prefecture to prevent soil erosion. In the present study, the researchers investigated the feasibility of extracting essential oil from vetiver in comparison with commercial essential oil by examining the differences in oil extraction rate and fluctuation, in terms of the presence/absence of its season-dependent oil components. In this study, the two commercial essential oils from Indonesia and Sri Lanka that were used for comparison differed in composition. The major component of the essential oil extracted from vetiver in the present study was alcohol, including khusimol and vetiselinol, which was similar to the commercial essential oil from Indonesia. The oil extraction rate (per dry weight) in early summer was 0.62%, but it was 0.34% in early winter. On another note, there was almost no fluctuation in the essential oil components collected in each period. This finding suggested that it is easy to stabilize the quality when the essential oil will be produced commercially. Combining the agriculture and aroma industries via the production and marketing of essential oil from green belt vegetation will help prevent soil erosion and lessen marine pollution in the future.